This application is based on and incorporates herein by reference Japanese Patent Application No. Hei. 11-363143 filed on Dec. 21, 1999.
1. Field of the Invention
The present invention relates to a sealed-type electric compressor having an electric motor and a compression mechanism within a compressor housing, suitable for use in a refrigerating cycle of an automotive air conditioning system.
2. Description of Related Art.
JP-B2-5-32596 discloses an electric scroll compressor used for a refrigerant cycle. In this electric scroll compressor, a housing rotatably supports a main shaft, and the main shaft is connected to a motor rotor and a compression mechanism. A first refrigerant passage is provided within the main shaft, and extends in parallel with the axis of the main shaft. Further, a second refrigerant passage is provided within the main shaft. The second refrigerant passage communicates with the first refrigerant passage and radially extends. A refrigerant flows through the first and second refrigerant passages, and into the front housing.
In the conventional electric scroll compressor, the refrigerant is discharged from the second refrigerant passage at the location between the motor rotor and the compression mechanism. Thus, the refrigerant does not sufficiently cool the motor.
A first object of the present invention is to cool an electric motor effectively by using a suctioned refrigerant.
A second object of the present invention is to arrange a refrigerant passage at an optimum location to improve a compressor working efficiency.
According to a first aspect of the present invention, a refrigerant passage within a rotor shaft includes a first refrigerant passage extending in parallel with a rotor shaft from the end surface thereof, and a second refrigerant passage communicating with the first refrigerant passage and extending radially outwardly. The second refrigerant passage is located between the end surface of the rotor shaft and a motor rotor.
Thus, when the rotor shaft rotates, suctioned refrigerant is uniformly sprayed toward a stator. Further, the refrigerant flows toward a compression mechanism through the electric motor, thereby cooling the electric motor effectively.
According to a second aspect of the present invention, a bearing supporter included at least two refrigerant passages for leading the refrigerant to the compression mechanism. At least one of the refrigerant passages is arranged close to an inlet port of the compression mechanism.
Thus, suction pressure loss is reduced, thereby improving the compressor efficiency.